This invention relates to self-sealing envelopes, for example, of the type used for mailing merchandise and, in particular, to an improved closure for an envelope of this type.
Envelopes for mailing merchandise have been made of a sturdy, flexible plastic material having a single flap at the open end of the envelope. In one conventional self-sealing envelope of this type, the flap has a band of pressure sensitive adhesive material extending across the flap covered by a protective peel-off tape. When the merchandise is inserted in the envelope, the protective tape is removed and the upper end of the envelope is folded down above the upper end of the merchandise to bring the flap and the pressure sensitive band into engagement with the outer surface of the envelope, thereby compactly sealing the merchandise within the envelope.
In the improved closure of the present invention, the envelope opening is defined between a pair of flaps, one taller and the other shorter. A band of pressure sensitive adhesive material, covered by a protective peel-off tape, extends across the inner surface of the taller flap, and the height of the shorter flap is such that when the merchandise has been inserted in the envelope and the shorter flap is interfaced with the taller flap, the upper end of the shorter flap adheres to the lower region of the pressure sensitive band to seal the closure, leaving exposed the upper region of the adhesive band. When the upper end of the envelope is folded above the contents, the exposed region of the adhesive band can be adhered to the outer surface of the envelope across the width of the taller flap, thereby providing an effective closure for the envelope.
In a preferred embodiment of the present invention, side-by-side weakened tear lines are formed across the flaps below the pressure sensitive adhesive band to facilitate opening the envelope. In a preferred embodiment, small air vents are provided in the side edges of the envelope below the pressure sensitive adhesive band at both ends of the weakened lines to permit the escape of air from the envelope. Moreover, in a preferred embodiment, the shorter flap is initially detachably retained in a folded back position so that it will not be prematurely adhered to the adhesive band before the contents are inserted and the envelope is ready to be sealed.
For a more complete understanding of the present invention, reference can be made to the detailed description which follows and to the accompanying drawings.